Sonoma Valley Groundwater
- A new website has launched providing the most up-to-date information on the Sustainable Groundwater Management Act implementation in Sonoma County: www.sonomacountygroundwater.org
- Groundwater Banking: Aquifer Storage and Recovery Pilot Project
Sonoma Valley Groundwater Management Program
Groundwater resources have long played a significant role in the development, growth and sustainability of the Sonoma Valley, with more than half the water demand in a given year met by local groundwater resources. With increasing local demands, assuring sustainable groundwater supplies in the Sonoma Valley may be difficult unless appropriate actions are taken in the near future.
These groundwater resources are relied upon by rural and urban residents, vineyards and wineries, dairies, and other businesses and also support the rich ecosystems present in Sonoma Valley. Assuring sustainable groundwater supplies in the Sonoma Valley is critical to the environmental health and economic vitality of the Basin. In recognition of the importance of local groundwater resources, local agencies and stakeholders have funded and supported technical studies and voluntary groundwater management programs that provide a strong technical and institutional foundation to build upon under SGMA. The USGS completed studies and modeling of the basin in 2006, and basin stakeholders engaged in a voluntary Groundwater Management Program between 2007 and 2017. Key information, tools and outcomes from these previous groundwater management planning activities include:
- Technical information on the Basin hydrology, hydrogeologic framework, water chemistry and source, surface water and groundwater interaction monitoring, and records of groundwater levels, including historical trends and documentation of two depressions in southern Sonoma Valley.
- Development of a MODFLOW groundwater flow model of surface water and groundwater systems in the Basin and contributing watershed area.
- Engagement of local stakeholders in local groundwater planning and management.
Further information and details on these studies and voluntary management work are provided in the following key studies that document the conditions of the Sonoma Valley groundwater basin:
- 2014, Sonoma Valley Groundwater Management Program. Five-Year Review and Update Report
- 2007, Sonoma County Water Agency. Sonoma Valley Groundwater Management Plan
- 2006, U. S. Geological Survey. Geohydrological Characterization, Water-Chemistry, and Ground-Water Flow Simulation Model of the Sonoma Valley Area, Sonoma County, California.
In 2017, as the Sonoma Valley Groundwater Sustainability Agency was forming and beginning to assume management responsibilities for the Sonoma Valley Groundwater Subbasin under the Sustainable Groundwater Management Act (SGMA), the Basin Advisory Panel and Technical Advisory Committee developed the Insights and Recommendations, Sonoma Valley Groundwater Conditions and Management document. In addition to providing recommendations for consideration by the GSA, the document also includes an attachment that summarizes the current understanding of groundwater conditions in Sonoma Valley.
Sustainable Groundwater Management Act
In September 2014, Governor Brown signed legislation requiring that California’s critical groundwater resources be sustainably managed by local agencies. The Sustainable Groundwater Management Act (SGMA) gives local agencies (cities, counties and water districts) powers to sustainably manage groundwater over the long-term, and requires Groundwater Sustainability Agencies (GSAs) be formed and Groundwater Sustainability Plans (GSPs) be developed for medium- and high-priority groundwater basins. The Sonoma Valley groundwater sub-basin (as defined in DWR’s Bulletin 118 and shown on Figure 1-1) is currently identified as a medium priority basin and is, therefore, subject to the requirements of SGMA.
In May 2018, DWR proposed elevating the Sonoma Valley basin to a high priority basin. Public comment is open until August 20th, 2018 with final prioritization in mid-October. The proposed change is not expected to have any immediate impact on the development of the Groundwater Sustainability Plan or other GSA activities, as medium and high priority basins are subject to identical requirements and timelines under SGMA. Public comment on the proposed reprioritization is open until August 20th, 2018 with final prioritization in mid-October. View a map of these groundwater basins on the Department of Water Resources website.
The Sonoma Valley Groundwater Sustainability Agency is developing a new groundwater sustainability plan, which must be completed by 2022. The existing GMP forms a strong foundation upon which to build in the development of the new GSP.
For further information on the new groundwater law and SGMA activities in Sonoma County, visit SonomaCountyGroundwater.org.
Important Info & Documents
- Basin Advisory Panel Insights and Recommendations
- 2015 Annual Report
- Five Year Review and Update Report, March 2014
- Water Efficiency Program - Rebates on high-efficiency toilets and clotheswashers and a High-Efficiency Fixture Direct Install Program for high-efficiency toilets and more
- View information on the Sonoma Valley Stormwater Management/Groundwater Recharge Scoping Study
- Five Year Review and Update Report, March 2014
- Five Year Review and Presentation on March 31, 2014
- Presentation by the Sonoma County Permit & Resource Management Department, April 17, 2014
- Presentation: Sonoma Valley Water Supply Conditions & Water Management Programs to the Sonoma Valley Citizens Advisory Commission, January 22, 2014
- Presentation: Sonoma Valley Groundwater Management Program to North Bay Agricultural Alliance, January 22, 2014
- Presentation: Five-Year Update and Review to Basin Advisory Panel, December 12, 2013
- Presentation: Sonoma Valley Water Supply Reliability to the Sonoma City Council, June 2013
- Presentation: Sonoma Valley Salt and Nutrient Management Plan, April 2013
- Presentation: AB3030 Monitoring Well Project
Sonoma County Water Agency